Conventionally, some approaches have been made to reduce on-water resistance of an amphibious vehicle.
For instance, Patent Document 1 discloses an amphibious vehicle, without crawlers, including side covers disposed on both side surfaces of a vehicle body so as to cover upper parts of wheels during traveling under water or on water.
Patent Document also discloses a tracked amphibious vehicle including crawlers which are mounted with many blocks formed of a light-weight material such that the crawlers act as a float.